The protective effect of an extract of Salvia miltiorrhiza Bunge (Danshen) on cerebral ischemic injury in animal models: A systematic review and meta-analysis

Cerebral ischemia is a common disease that seriously threatens the health of human beings. Tanshinone IIA (TSA) is a fat-soluble compound isolated from the traditional Chinese medicine Danshen. Recent studies have shown that TSA plays a significant protective role in the animal models of cerebral ischemic injury.The meta-analysis was to evaluate the protective effect of Danshen (Salvia miltiorrhiza Bunge) extract (TSA) in cerebral ischemic injury, aiming at providing scientific evidence for clinical application of TSA in the treatment of cerebral ischemia in patients.All relevant studies published in PubMed, Web of Science, Cochrane Library, China National Knowledge Infrastructure (CNKI), Wanfang Database, Chinese Scientific Journals Database (VIP) and Chinese Biomedicine Database (CBM) before Jan 2023 were systematically retrieved. The methodological quality was assessed by SYRCLE's risk of bias tool for the animal studies. Data was analyzed using Rev Man 5.3 software.A total of 13 studies were included. Compared with the control group, TSA significantly reduced the expression of glial fibrillary acidic protein (GFAP) (mean difference [MD], -1.78; 95% CI, [-2.13, -1.44]; P < 0.00001) and high mobility group protein B1 (HMGB1) (MD, -0.69; 95% CI, [-0.87, -0.52]; P < 0.00001). TSA also inhibited the activation of brain nuclear factor κB (NF-κB) (MD, - 0.36; 95% CI, [-0.41, -0.32]; P < 0.00001), malondialdehyde (MDA) (MD, -0.90; 95% CI, [-1.66, -0.13]; P = 0.02), cysteine protease-3 (Caspase-3) (MD, -1.39; 95% CI, [-1.98, -0.81]; P < 0.00001), and reduced cerebral infarction volume(MD, -16.26; 95% CI, [-20.76, -11.77]; P < 0.00001), brain water content (MD, -4.89; 95% CI, [-7.06, -2.71]; P < 0.0001) and neurological deficit scores (MD, -1.19; 95% CI, [-1.48, -0.89]; P < 0.00001). Additionally, TSA increased the brain content of superoxide dismutase (SOD) (MD, 68.31; 95% CI, [10.41, 126.22]; P = 0.02).The result of this study showed that TSA had a protective effect on cerebral ischemic injury in animal models, and the mechanism is associated with the reduction of inflammation and oxidative stress, and the inhibition of cell apoptosis. However, the quality of included studies may affect the accuracy of positive results. Therefore, more high-quality randomized controlled animal experiments are need for meta-analysis in the future.